In modern society, energy and environment protection have become a main problem faced by people. An LED has achieved a daily increased attention in a lighting field, due to a plurality of advantages thereof, including: a high efficiency, a low energy consumption, an environment protection, a small volume, a long lifespan, and more. However, limited by a character of optical and electrical, the LED requires a special constant current driving circuit as a supplement before being able to work properly, so an importance of an LED driving system is self-evident.
In an integrated circuit system, the existing LED driving systems are mainly adopting a work method of a single mode control, generally, a voltage mode or a peak current mode is adopted to work, usually, it includes three parts: current sampling-feeding back-circuit control. Wherein, for the part of circuit control, usually it is an analog method, that is, a process of controlling a change of a duty circle through comparing a sampling signal and a fixed voltage, and further controlling a change of an output voltage. A plurality of main defects of such an invention is as follows: first, the work mode is single, a system stability is general, a response speed is slow due to it is required to experience a whole system adjustment process from the current sampling to feedback control; second, the part of circuit control is mainly a simple comparison process, with a relatively low accuracy, causing a range of the output voltage after feeding back too large, additionally, subjecting to an effect of a plurality of environment factors including a process deviation, a temperature, a humidity and more, it may also cause the accuracy of the control part decrease; third, a generality of the system is relatively poor, usually, a driving system is mainly specialized, in a real implementation, a plurality of applications including changing a condition, increasing or decreasing a function, is hard to be achieved.
Therefore, the current technology needs to be improved and developed.